1. Field of the Invention
The present invention relates to a fallboard arrangement for a keyboard instrument, which is capable of opening and closing a performance section of the keyboard instrument by sliding a fallboard of the keyboard instrument.
2. Description of the Related Art
Conventionally, as a fallboard arrangement for a keyboard instrument, there has been known one disclosed e.g. in Japanese Laid-Open Patent Publication (Kokai) No. 2000-305556. The fallboard arrangement is applied to an electronic piano, and includes a fallboard. The fallboard is mounted on the piano body of the electronic piano such that it can slide in a front-rear direction between a closed position for closing a performance section of the electronic piano and an open position for opening the same. The fallboard has a laterally elongated fallboard front section secured to the front end thereof with screws, and left and right front guide protrusions protruding from the lower end of the fallboard front section. The front guide protrusions protrude outward from the respective left and right ends of the fallboard front section, and are engaged with front guide grooves of respective left and right arms of the piano body.
Further, the fallboard has a laterally elongated fallboard rear section secured to the rear end thereof with screws, and left and right rear guide protrusions and left and right pinions protruding from the fallboard rear section. The left and right pinions protrude outward from the respective left and right ends of the fallboard rear section, and are in mesh with racks of the respective left and right arms of the piano body. The left and right rear guide protrusions protrude further outward than the left and right pinions, and are engaged with rear guide grooves of the respective left and right arms of the piano body.
With the above-described arrangement, in the fallboard arrangement, when the fallboard is manually drawn forward or pushed rearward, the front guide protrusions are guided by the respective front guide grooves, and the rear guide protrusions are guided by the respective rear guide grooves, while the pinions rotate in mesh with the respective racks. Thus, the fallboard slides in the front-rear direction while preventing large gaps from being formed between the upper edges of the respective arms and the associated lower edges of the fallboard during sliding of the fallboard. This is because if such gaps are formed, the appearance of the electronic piano is degraded, and there is a fear that smooth sliding of the fallboard can be hindered due to entrance of foreign matter into the gaps.
As described above, according to the fallboard arrangement disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2000-305556, with a view to ensuring good appearance and smooth opening and closing operation, it is required to prevent large gaps from being formed between the upper edges of the respective arms and the lower edge of the fallboard during sliding of the fallboard in the front-rear direction. For this reason, the upper edges of the arms and the front guide grooves are limited in positional relationship therebetween and shape, which results in a low degree of freedom of design.